7mm Remington Magnum

History

When the Mauser brothers designed the 7x57 cartridge for use in their M93 military bolt action rifle, the excellent qualities inherent in the 7mm bore diameter soon became apparent to cartridge designers all over the world. Here was a cartridge that produced a flatter trajectory than most of its competition, minimal wind drift and potentially, optimum terminal performance at extended ranges. Following these discoveries, cartridge designers began to experiment with larger cases to maximize down range performance.

One of the earliest high power designs was the .280 Ross, designed by F.W Jones for the Ross rifle company of Quebec, Canada in 1906. This cartridge featured a rimless case, not too dissimilar to the 7mmRUM. The Ross rifle and cartridge were intended primarily for military use however the rifle locking mechanism had some short comings which proved undesirable.

The British were also very interested in driving 7mm bullets at maximum velocities. Holland & Holland introduced the .275 H&H Magnum in 1912, based on a shortened version (2.5”) of their .375 H&H cartridge case, featuring the typical H&H smooth feeding tapered case deign. The British military tried to follow on from this with the creation of the .276 Enfield prototype cartridge and P14 rifle to house the large 7mm magnum. Unfortunately for Enfield designers, war and politics halted any further experimentation. These early cartridges, the Ross, H&H and Enfield generally achieved 2900fps with 140 grain bullets. Higher velocities were not quite yet obtainable due to the limits of powder design. Throat erosion was also very severe.

The first truly potent magnum sevens to be created were the 7x61 Sharp and Hart and the 7mm Weatherby magnum, both U.S inventions, introduced during the early 1950’s. While the cartridge designs were somewhat similar to the .275 H&H, albeit blown out to minimize body taper, the major breakthrough was the adoption of surplus 20mm cannon powder. This slow burning powder enabled huge increases in velocity. Nevertheless, although the 7x61 and Weatherby were very good cartridges, neither had become mainstream offerings which limited ammunition availability and effected pricing.

Following the introduction of the 7mm Weatherby and 7x61, American gun writer Warren Page of 'Field & Stream' magazine was noted, among others, for promoting the idea that America needed a standardized Magnum 7mm cartridge chambered in a standard production rifle, easily obtainable from any gun store. Wildcatter Art Mashburn had recently designed a very appealing candidate based on the .300 (or .375) H&H case necked down to 7mm, this was similar to the 7x61 and Weatherby however rather than being shortened to 2.5”, the Mashburn featured a longer case at 2.620” as opposed to 2.5” resulting in a noticeable increase in powder capacity.

Warren Page had Art Mashburn chamber one of his rifles for the 7mm Mashburn Super Magnum and Page was ecstatic over the results. The Mashburn was able to drive a 160 grain bullet at 3200fps and for medium game hunting at both close and longer ranges, the Mashburn was an emphatic killer.

The situation became heated when Jack O'Connor gifted his .275 H&H magnum (load at the time was a 175 grain bullet at 2680fps) to wildcatter Les Bowman. Impressed with the idea of a 7mm magnum, Bowman in turn had a .338 Win Mag necked down to 7mm by Fred Huntington of RCBS, naming it the .280 Remington Magnum. Bowman had no trouble impressing his friend Mike Walker of Remington with the new cartridge. Recoil levels were approximately the same as the ever popular .30-06 yet the 7mm produced a much flatter trajectory and excellent down range terminal performance. In 1962, after much experimentation at the Bowman ranch, Remington released the 7mm Remington Magnum. Almost overnight it made several fine cartridges near obsolete, among them the .264 Winchester Magnum.

The 7mm Remington Magnum is currently an extremely popular medium game hunting cartridge, performing exceptionally well at long ranges. It was at one time utilized by the U.S secret service for specialized operations however exact information on its usage is sketchy at best.

The 7mm RM is available in a wide range of rifle configurations. Barrel lengths also differ from maker to maker. For many years, a common barrel length for sporting rifles was 24”. This is slightly too short for optimum performance, not only because of the 70fps reduction is velocity, but the shorter barrel raises both noise and recoil.

Performance

The 7mm Remington Magnum is definitely one of the most effective, versatile medium game cartridges available to hunters around the world. The two major complaints of its design are the short neck and belt. The short neck can sometimes effect bullet to bore alignment however this usually poses few problems and most hunters (hand loaders) never witness adverse effects. The belt is certainly an unfortunate accessory. It serves no purpose other than to make the cartridge ‘look’ like a magnum. The belt can cause feeding problems in rifles with already poor feed design. The remedy for this is correct insertion of cartridges into the rifle magazine. When a magazine is filled, it is important to ensure each case is pushed back as far as possible before placing another cartridge in the stack. With attention to practices, the belt soon becomes completely irrelevant and cycling is smooth and fast. It has been said that the belt helps thicken the primer pocket area and helps to maximize case life with warm hand loads. There is possibly a small amount of truth to this statement.

With 140 grain bullets, driven at velocities of between 3200 and 3300fps, the 7mm RM delivers extreme trauma on light bodied game out to ranges exceeding 400 yards. This bullet weight tends to lose its ability to produce wide wounding at ranges of around 650 yards. On heavily built medium game, the 140 grain bullet can produce somewhat less than ideal performance, wounding and penetration may be adequate but results can be erratic.

Loaded with 150-154 grain bullets driven between 3100 and 3200fps, the 7mm RM is devastating on a wide range of game out to ranges sometimes exceeding 900 yards. This bullet weight is more versatile than the lighter 140 grain weight but is still somewhat limited on large, heavy bodied medium game although wounding and penetration are more uniform. This bullet weight is best suited to game weighing less than 80kg (180lb).

The 160-180 grain bullet weights are the most versatile performers in the 7mm RM. Providing bullet construction is matched to the job at hand. The heavy weight 7mm projectiles can be used on the lightest of game through to animals weighing up to 320kg, producing fast clean killing out to 1000 yards. On game heavier than 320kg, the 7mm RM is capable of producing adequate penetration but not wide wounding relative to body weights. For this reason, if the 7mm is to be used on large heavy animals, neck and head shots are the most humane means of obtaining fast kills. For ordinary chest shots, the .30 caliber and medium bores provide much broader wounding through vital tissues.

The 7mmRM produces mild recoil in medium weight rifles with straight recoiling stock designs. In light weight rifles or rifles featuring Monte Carlo style stocks, felt recoil can be uncomfortable. It has been said that one of the goals of Remington in designing this cartridge was to duplicate the power and recoil levels of the .30-06 in order to ensure mainstream acceptance.

Unfortunately, the current trend towards light weight barrels does not help minimize recoil of the 7mm RM or any of the magnums. Factory rifles are available with either No.2 contour barrels (light sporter) or No.5 Contour (Varmint) as can be found on the Remington Sendero. No.3 and 4 contour medium weight barrels are found only on Sako rifles or through custom barrel makers. Barrel length is also a concern, several manufacturers continue to produce 24” barreled magnums while optimum barrel length is 26” for normal use through to 28” for open country hunters and long range enthusiasts.

The traditional Core-Lokt is one of the best conventional bullets on the market, with relatively inexpensive economy while offering fast killing and adequate penetration. The 150 grain bullet is a reliable all-rounder but has a low BC and is not an emphatic killer beyond 275 yards. The 175 grain bullet makes an excellent bush/woods load. On smaller whitetail/ Sika sized game with tail on shots, the 175 grain bullet smashes through pelvis bone, renders huge internal damage and punches out through brisket bone coming to rest in neck or shoulder muscle weighing around 120 grains.

Remington’s latest 140 and 160 grain Core-Lokt Ultra projectiles perform extremely well on medium game but the low BC’s of .409 and .415 respectively make these projectiles susceptible to wind drift, bullet drop along with reduced wounding potential at ranges beyond 275 yards as velocity sheds rapidly. The 150 grain Accutip has a BC of .530 and is a spectacular killer on medium game. This is not an exceptionally deep penetrating projectile but is the most useful of the Remington range for hunters wanting a load suitable for use on medium game out to long ranges. Unfortunately, the Accutip is priced beyond the reach of most hunters.

The 150 grain Scirocco has an excellent BC of .533, wounding at close to moderate ranges is very broad and deep with wound diameters steadily decreasing as ranges exceed 300 yards. The Scirocco reaches its limits but is highly effective on tough game such as mature Boar and Thar, on thinned skinned game, the larger bodied deer species including Elk are the absolute limit for this projectile. Like all core bonded designs, the Scirocco is not a particularly good choice for long range work due to limited expansion at low velocities. The A Frame is designed for maximum penetration on large game such as Elk, Moose and a variety of African plains game. Like all 7mm projectiles, wounding on large heavy animals is limited due simply to the limitations of this bore diameter and associated bullet weights. The A Frame has a poor BC relevant to its primary function and performs best at close to moderate ranges.

Current entry level offerings from Winchester include the traditional 150 grain PowerPoint at an advertised 3090fps and 175 PowerPoint at 2860fps. These loads give around 70fps below advertised velocities in 24” barrels, the 150 grain PP is a spectacular killer at moderate ranges but suffers total bullet disintegration when striking light bone in bush/woods hunting situations. The 175 grain bullet is similarly soft in construction to ensure wide wounding however penetration is somewhat deeper than the 150 grain counterpart. Neither are particularly good choices for heavily built medium game and BC’s for both loads are low. Nevertheless, the PowerPoint loads are economical and spectacular lighter medium game bullets producing acceptable performance out to 300 yards or so.

Winchester’s Supreme loads include the 140 grain Ballistic Silvertip at 3100fps, the 140 grain Nosler Accubond at 3180fps, the 150 grain Ballistic Silvertip at 3100fps and the 160 grain Nosler Accubond at 2920fps, all achieving stated velocities. The 140 and 150 grain Ballistic Silvertip are designed purely for open country lighter medium game work and while both of these bullets produce wide wounding, the 150 grain BT (BC .493) is the more spectacular killer of the two. The slight increase in SD allows this projectile to bore a much deeper, wider, fast killing wound than its 140 grain counterpart, regardless of body weights encountered. The 150 grain BT reaches its absolute limits with regard to reliable penetration on game weighing 80kg (180lb).

Winchester's Accubond loads produce excellent performance on medium game. A major advantage of the Accubond design is its extremely fast expansion combined with the ability to shed frontal area to a reduced diameter, ensuring reasonably deep penetration. The 140 grain Accubond is sometimes accused of suffering bullet blow up due to large onside entry wounds however this is seldom the case. The main problem with the 140 grain bullet is that, like all 140 grain 7mm projectiles, it is often employed on large bodied game (over 80kg) on which the higher SD 160 grain bullet is much better suited. Where resistance is too great and velocity too high, the 140 grain bullet will indeed suffer either limited penetration or simply a reduction in wounding potential after initial impact (first 1” penetration). The 160 grain Accubond (BC .512) is more consistent in this regard, producing very uniform wounding. Kills are never spectacular but quick nonetheless. Being a core bonded design, fastest kills are obtained inside 275 yards. Beyond this range, killing is often slightly delayed with rear lung shots.

Winchester’s heavy game loads include the140 grain Failsafe (BC .337) at 3150fps and the 160 grain Failsafe (BC .384) at 2920fps, both are best suited to stout game, the 160 grain bullet is adequate but not ideal for Elk and Moose. These projectiles are slow killers if shots do not strike major bone or the CNS due to narrow wounding.

In the past, Federal loads were abysmal in the velocity department. Loads were anything from 150 to 250fps below advertised specs. Today, Federal ammunition is either true or close to advertised barrels relevant to barrel lengths.

Federal’s traditional Vital-Shok loads are adequate but not outstanding in performance. The most positive aspects of the Vital-Shok line are pricing in comparison to other brands combined with excellent moderate range (300 yard) accuracy. Disadvantages include low BC’s resulting in a rapid loss of velocity and therefore hydrostatic shock. Wounding tends to be wide at close to moderate ranges however the Vital-Shok (Hi-Shok) projectiles are neither deep penetrating nor explosive.

Federal’s 150 grain GameKing is an interesting load. This is a proprietary bullet as opposed to the standard 150 grain GK that hand loaders have access to. The Federal version features a cannelure which helps arrest expansion, either minimizing or delaying jacket core separation. The 150 grain GK is explosive at impact velocities above 2700fps and equally violent but not prone to total disintegration at lower velocities. This load is best suited to lighter medium game up to a maximum weight of 80kg (180lb) and the cannelure helps greatly to minimize early bullet blow up.

The 150 grain Ballistic Tip and Solid Base boat tail bullets are, like the GameKing load, designed for open country hunting of medium sized deer species. All three bullet designs, the GK,BT and SBBT perform identically with regard to ideal body weights and ranges, the only difference being the slightly softer, slightly less brittle nature of the Nosler bullets, though the differences are subtle. Federal try to cover all of the market with a wide choice of ammunition but ultimately, such saturation often leads to confusion. The same can be said for the Barnes and TBBC loads. Hunters are advised in this regard, to shop based on price.

The Federal 160 grain Partition and Accubond loads are excellent all round performers on medium game. The Partition is the more spectacular killer of the two, a simply outstanding hunting bullet for light through to large medium game weighing around 320kg (700lb). The Partition is dramatic in performance out to a range of around 275 yards (2400fps) and continues to produce wide wounding down to 2200fps (400 yards), with a gradual reduction in wounding as velocity approaches 2000fps (525 yards). The Accubond has a higher BC than the Partition for longer range hunting but unfortunately, does not duplicate the explosive killing power of the Partition at normal hunting distances (inside 300 yards). Furthermore, even though its BC is higher than the Partition, in real world terms, the Accubond breaks 2200fps for example, at around 450 yards, as opposed to 400 yards for the Partition.

Federal’s 165 grain GameKing is another proprietary bullet given the same cannelure treatment as its lighter counterpart. The 165 GameKing is not the most flexible bullet, slightly too stout for consistently fast kills on light bodied game yet to fragile for heavy bodied game. This load is best suited to game weighing right on the 80kg mark (180lb) out to ranges of around 400 yards.

Federal’s 160 grain Barnes Triple Shock and Trophy Bonded Bear Claw loads are best suited to large, heavy bodied medium game. These are deep penetrating projectiles, capable of full cross body penetration (and exit) on game weighing as heavy as 700kg (1540lb). That said, and this cannot be reiterated enough, the 7mm bore does not have the wounding potential of a wider caliber therefore, although penetration is outstanding, if using the Barnes or TBBC loads on heavy game, shots should always be directed into the head neck area.

PMC’s standard Bronze line features a 140 grain soft point at 3100fps, a 160 grain soft point at 2900fps and a 175 grain soft point at 2860fps. PMC’s semi premium Silver line features the 140 grain Sierra GameKing at 3125fps and 160grain GameKing at 2900fps while the Gold line features the 140 grain Barnes XLC at 3000fps and 160 grain XLC at 2800fps. These PMC loads generally duplicate the Federal range which also features Sierra and Barnes bullets. PMC is well known for economy, velocities of the Bronze line often fall below advertised specs however, the Silver and Gold brands tend to produce close to advertised velocities.

Hornady loads include the 139 grain Interlock BTSP at 3150fps, the 139 grain InterBond at 3150fps, the 139 grain GMX Superformance at 3190fps, the excellent 139 grain SST Superformance at 3240fps, a choice of the 154 grain Interlock, InterBond and SST at 3035fps, the 162 grain Interlock BTSP at 2940 and finally, one of the best loads available, the 162 grain SST Superformance at 3030fps. These velocities are all obtained from a 24” test barrel and as always, run true to Hornady’s claims.

The 139 grain Interlock load is like most 139-140 grain 7mm loadings, fairly mild in performance. As an entry level offering, the Interlock is relatively inexpensive and produces fast, clean killing on lighter medium game. Penetration is fair but not immensely deep with this soft projectile.

Hornady’s 139 grain InterBond is an excellent medium game bullet. This load gives best performance at impact velocities above 2400fps (400 yards), after which, wound channels can be narrow although clean kills can be obtained at impact velocities of 2000-2200fps with careful shot placement. The 139 grain InterBond tends to produce what is perhaps best described as ‘contained’ wounds. Rather than the violent explosive wounding produced by the SST, wounds produced by the InterBond tend to be more uniform and centralized, certainly better for meat retrieval. This load is well suited to game weighing up to and around 80kg and is effective on stout/tough bodied animals.

The 139 grain SST Superformance load is truly outstanding on lighter medium game and the muzzle velocity of 3240 suits the SST very well. Jacket core separation is common with the projectile however the SST does not appear to suffer problems during the critical stages of broadside/quartering penetration. This is generally a moderate recoiling load and can be relied on to produce clean kills out to 700 yards. The 139 grain SST is not well suited to large bodied game and 80kg is an absolute limit for this bullet. It is a pity that Hornady have not produced an identical velocity InterBond load as the two can be used without any shift in POI, the InterBond for close to moderate range work, the SST for open country hunting.
Hornady’s latest offering, the GMX, is a stout, solid copper projectile similar in nature to the Barnes range of projectiles. I have not yet had a chance to test this projectile.

Of the medium weight offerings, the Hornady 154 grain SST and InterBond make for an extremely effective combination. The 154 grain SST is devastating on lighter medium game, reaching its limits, regarding cross body penetration, on game weighing around 90kg (200lb) when used at close ranges. The 154 grain InterBond is much more reliable at close ranges, producing deep, broad wounds and fast killing out to 250 yards, producing clean kills out to 400 yards. The InterBond is adequate for game weighing up to 320kg while the SST needs room to lose velocity before it is able to tackle larger medium game. Used within the 90kg body weight range, the 154 grain SST, at the listed velocity of 3035fps, is unusually effective out to 950 yards providing major muscle or bone is encountered on impact.

Hornady’s 162 grain Interlock BTSP is a traditional, conventional soft point offering. This is an entry level/economy load yet is very effective. The 162 BTSP has a generous BC of .514 and is generally easy to work with regarding potential accuracy. The Interlock tends to lose a great deal of weight during penetration and on raking shots, average retained weight of projectiles tends to be around 68 grains. In contrast, the InterBond retains an average 70% weight while the 162 grain SST normally retains 50% of its original weight. The comparisons are all relative to close range woods/bush situations. The 162 grain Interlock BTSP tends to produce very violent fast killing wounds on lighter medium game at ranges of up to 250 yards. Wounding is not as severe as the SST however kills are nonetheless very emphatic. The 7mm 162 grain bullet is generally associated as being the ‘Elk’ bullet weight however the Interlock is not really in the same league as Federals partition load or Hornady’s 154 grain InterBond load, suffice to say, this load is better suited to game weighing up to 80kg and perhaps heavier (150kg) at a push.

The 162 grain SST is yet another outstanding projectile and at 3030fps, this offering from Hornady is spectacular. This bullet does not penetrate as deeply as for example the excellent Nosler Partition however once its limitations (strengths and weaknesses) are understood, this load can be used to great effect. The 162 grain SST is explosive whether it is used on 20kg game or 120kg game (44-264lb). At close ranges inside 100 yards, game weights of 150kg (330lb) are perhaps the upper limit if exit wounding is desired. Beyond 100 yards and especially as ranges increase beyond 300 yards out to around 950 yards, the SST is able to tackle heavy boned medium game such as Elk and Sambar. The 162 grain SST is adequate for large bodied game at close ranges but as previously mentioned, it is important to understand its limitations and not to place unrealistic expectations on the design, the SST will reach vitals but cannot be expected to produce full cross body (exit) penetration on large animals.

One last load that can’t be overlooked for Woods/ bush hunting is Norma’s 170 grain Vulcan. Advertised velocity is 3018fps giving around 2950fps in 24’ barreled sporters. The Vulcan is no long range bullet (BC of .35), having a blunt nose to initiate maximum hydrostatic shock transfer and is a violent killer at close to moderate ranges. Penetration from raking shots is outstanding on light to medium weight game. This projectile is also available as a reloading component projectile for those wishing to work up an excellent woods load.

Hand Loading

The most suitable powders for reloading the 7mm RM are the slow burn rates IMR4831/H4831sc/N165/RL22 through to H1000/RL25. Hodgdon Retumbo (ADI2225) is a little too slow in most instances. Brass for the 7mm RM is readily available throughout the world and is produced by several manufacturers.
Hand loaded for a 24” barrel, maximum safe working velocities include 3250fps with 140 grain bullets, 3150fps with 150 grain bullets, 3100fps with 154 grain bullets, 3050fps with 160-162 grain bullets and 2900fps with 175 grain bullets and the 180 grain VLD.

From a 26” barrel, velocities include 3320fps with 140 grain bullets, 3220fps with 150 grain bullets, 3120fps with 160-162 grain bullets and 2950fps with 175-180 grain bullets. As always and regardless of barrel length, individual rifles will show preferences, some producing best accuracy at higher pressures, other rifles producing optimum accuracy with low pressure charges. As an example, some rifles will shoot the 162 grain bullets with optimum accuracy at an MV of 3040fps, some will give best accuracy right at 3120fps, others will give best accuracy at both pressure levels (sweet spots), producing relatively poor groups with intermediate charges. Experimentation is the key.

For dedicated long range hunters, best velocities are achieved with 28-30” barrels capable of pushing the 162 grain A-Max at 3200fps and the 180 grain VLD at 3000-3050fps. Optimum twist rate for all bullet weights in the 7mm RM is 1:9”.

Accuracy is of vital importance when working up a 7mm magnum load. Any gain in velocity over a standard cartridge will immediately be negated if the rifle will not shoot better than these cartridges at the extended ranges for which magnums excel at. This applies not only to long range hunters but also to the hunter who expects clean killing at 300 yards. Poorly bedded rifles or rifles set up with unreliable optics produce abysmal results in the field, slow killing gut shots being the most common result.

As with most belted magnums, neck dies usually produce better accuracy than full length resizing dies. The only exceptions to this general rule are when reloading for rifles with minimum head space as well as semi auto rifles and unique action designs such as the Blaser rifle system. Not only do neck dies aid accuracy, but are also much quicker and cleaner to use than FL dies.

The Sierra MatchKing (SMK) bullets in 7mm are all very unreliable. At best, these can be used on stout animals such as wild boar at extended ranges. The tough hide and dense muscles of the wild pig ensure fragmentation. This is perhaps the only suitable hunting application for the SMK.

The 140 grain Sierra GameKing struggles to perform on game as light as 30kg (66lb) inside 150 yards at typical 7mm RM velocities. The GK breaks up on impact, will often produce a poor wound channel and fail to produce an exit wound. This is a slow killer and can be very cruel when used on 60-80kg animals. Sierra produce a stout 140 grain Pro-Hunter projectile. This bullet is much better than its GameKing counterpart when used at close ranges/high velocity but as a tradeoff, its flat base design leaves the Pro-Hunter with a less than desirable BC of .377. Nevertheless, the Pro-Hunter is a reliable lighter medium game bullet. Wound channels tend to be uniform, neither large nor too small and penetration is adequate for all but tail on shots.

The 150 grain Sierra GameKing is a spectacular killer on lighter medium game. At moderate ranges, neck shots result in near full decapitation while exit wounds from chest shots may be up to 3 inches in diameter and laden with copper fragments. Realistically this bullet is at its best on game weighing no more than 70kg (150lb) if used at close ranges. Once the GameKing drops below 2700fps (around 200 yards), expansion tends to be much more uniform rather than the instantaneous bullet blow up that occurs otherwise.

Sierra’s 160 grain GameKing is a tough bullet, designed for use on larger bodied deer in the Mule and Red deer weight ranges. This bullet is adequately suited to these applications out to ranges of around 500 yards. This bullet weight can be a little difficult for both bullet manufacturers and hunters alike to fully utilize. The jacket of the 160 grain GK is stout to ensure acceptable penetration however at long ranges (the forte of the 7mm RM) a stout jacket can be undesirable. Nevertheless, the 160 grain GK fills a niche, suitable for open country hunting of medium sized game at ordinary hunting ranges.

For woods hunters, the 170 grain round nose Pro-Hunter packs a punch. Sierra definitely know how to make a round nose bullet perform. The Pro-Hunter is best loaded to full or near full velocities, resulting in emphatic kills at close ranges. If full length penetration (tail on) is a requirement, the 170 grain RNPH can be downloaded to between 2600 and 2700fps using H1000 powder. This reduction in velocity helps minimize the loss of SD during penetration.

Sierra’s heaviest bullet is the 175 grain GameKing. This bullet is designed for use on large bodied deer (Elk) in open country at extended ranges. Unfortunately, the 175 grain GK is handicapped by a low (for its weight) BC of .533. Best performance occurs at impact velocities above 2200fps or from an MV of 2900fps, 425 yards. Sierra really need to explore 7mm/heavy bullet design further as there is great need of a 175-180 grain soft jacketed BTSP, suitable for hunting light to medium weight game out to 1000 yards. This company certainly have the ability, considering the frangible nature of the 130 grain single shot pistol bullet (further reference in 7x57 text).

At 7mm RM velocities, Speer’s 130 grain bullets are too light for reliable performance on medium although the 130 grain Hotcor can be very spectacular. The 145 Speer Hotcor and BTSP are an acceptable light game combination however this bullet weight is still not as effective as Speer’s 160 grain offerings. The versatility when dual loading Speer’s 160 grain bullets is quite outstanding.

The highly frangible Speer 160 grain BTSP (BC .519) is an excellent bullet. On light bodied game, the BTSP is perfect for both close and intermediate long range hunting out to 650 yards. On tougher medium game, the BTSP should be reserved for longer range shots were velocity is below 2600fps (275 to 650 yards) to minimize early bullet blow up. For large bodied game at close ranges, the Hotcor is the better performer. Although the 160 grain BTSP has a fairly low BC of .519 (compared to the A-Max or VLD), the Speer BTSP is a good option, especially during production shortages of other brands. Speer really need to produce a 175 to 180 grain BTSP to round off their line, such a bullet would be incredibly effective at long ranges if a high BC could be obtained.

Speer’s 160 grain Hotcor (BC .504) is a good performer on animals over 80kg (176lb) and up to 150kg (330lb). On animals lighter than 80kg, the Hotcor tends to give slow kills with lung shots, allowing animals to escape long distances. The Hotcor fully expands on light game but simply does not do so instantly and requires suitable resistance at the target to initiate fast expansion. This bullet usually holds together giving adequate penetration at awkward angles on medium game. The Hotcor imparts tremendous amounts of shock once the right amount of resistance is met and if fired into test medium, shows a larger wound channel than most .30 caliber bullets. It's ability to produce vast hydrostatic and hydraulic shock gradually falls off below 2500fps (300 yards) giving clean but delayed kills at velocities of 2400fps (375 yards). This is a good bullet for larger bodied deer species.

Speer’s 160 grain Grandslam is similar in performance to the Hotcor, both have their limitations when striking heavy bone however after having three 160 grain Grandslam projectiles suffer complete blow up on bone at ranges of 30 to 50 yards from muzzle velocities of 2900fps through to 3000fps, I cannot recommend this bullet. That said, every maker has a bad batch from time to time so it pays not to be too absolute when studying single batch lots.

The 145 and 160 grain Trophy Bonded Bear claw are both very stout bullets. This design is best used at close to moderate ranges where velocity is high. Wounding below 2600fps tends to be somewhat limited in comparison to other bullet designs. Nevertheless, for tough, densely muscled game, the TBBC bullets produce optimum wounding and penetration in a consistent and reliable manner. The TBBC (both weights) are well suited to Elk sized game.

Of the two conventional 139 grain projectiles Hornady’s 139 grain BTSP is designed specifically for magnum velocities. However; like most conventional bullets of this weight, the BTSP is still rather soft. Both of these Interlock projectiles are softer than the 140 grain Sierra Pro-Hunter and 145 grain Speer Hotcor.
The 139 grain Hornady SST is an excellent and often spectacular open country load when used on light bodied game. As mentioned in the factory ammunition section, maximum effective range for the 139 grain SST is around 700 yards. Beyond this, the 139 grain weight does not really have the mass or energy needed to initiate maximum bullet expansion and mechanical wounding. The 139 grain InterBond is ideal for use on light to medium sized game out to 300 yards and adequate out to 400 yards. The InterBond is a most emphatic killer on wild pigs weighing up to 80kg. Both the SST and InterBond can be used as a dual load to increase flexibility.

The 154 grain Hornady Interlock only has a BC of about .43 but it performs well out to 300 yards. It retains about 50% of its weight after impact and is effective on a broad rage of medium sized game. The Interlock will often exit medium game and leaves a good blood trail. On large, heavy boned medium game, the 154 grain Interlock can suffer blow up if major ball joints are encountered during penetration. The 154 grain SST, as discussed in the factory ammunition section is an impressive open country lighter medium game bullet. For long range hunting, the SST is surprisingly violent if major bones are hit out at distances as far as 1000 yards. Like the standard 154 grain Interlock, retained weight is usually around 50% although greater weight loss occurs when this bullet is used on large bodied deer.

Hornady’s 154 grain InterBond is extremely useful out to moderate ranges. Hand loaders can optimize performance of this bullet by annealing the ogive. Use a candle flame, ensure the flame is long, hold the projectile gently with poly grips (make sure the teeth on the grips/pliers are blunt) and roll the ogive of the InterBond through the flame. This action should be done very slowly, over the course of 8-10 seconds. After this, place the projectile on a bench and allow it to cool slowly. Wipe the projectile clean of soot and check its temperature if bullet seating operations are to follow. (DO NOT ANNEAL LOADED AMMUNITION). One only need anneal 5-6 projectiles and put these aside for special situations, using the standard IB for practice etc.

Annealing the InterBond enhances performance in two ways. Firstly, the projectile expands much more readily on impact which is important for use at ranges between 275 and 400 yards. Secondly, rather than expanding to double diameter and losing sectional density, the frontal area is able to swage back after expansion for much deeper penetration than is normally obtainable with this bullet. Once annealed, tail on shots on lighter medium game result in clean, fast kills. Unfortunately, annealing the 154 grain SST produces no noticeable benefits.

Hornady’s traditional 162 grain Interlock BTSP is a fast killer, full expansion occurs at both close range and long ranges where velocity is low or game resistance is light. This is not a deep penetrating bullet, even on game as light as 60kg (130lb) however the Interlock will reach vitals of medium game from most angles. The 162 grain Interlock is a cheap bullet to work with and it is always good to have a stock of this bullet for practice, initial load development, hunting of light to medium weight game under 90kg (200lb) or to fall back on when desired premium brands are unobtainable.

The Hornady 162 grain SST bullet is one of the very best all-round projectiles available for the 7mm Rem Mag. The only major difficulty with this projectile, is that in custom barrels with shallow throat lead angles designed for the A-Max and VLD, the SST can be hard to get shooting accurately. The 162 grain SST produces a wide wound channel and relatively deep penetration. Where deep penetration is required, such as for use on large bodied medium game, the 162 grain SST should be annealed in candle flame as described above. The SST has a stout jacket which, after its explosive impact, often stays at too large a diameter for maximum terminal performance. Annealing the ogive enables the frontal area to swage back against the shank for deeper, more uniform penetration. Weight retention is around 50% for both the standard and annealed 162 grain SST however annealing minimizes incidents of bullet blow up or basic jacket core separation.

In rifles that will shoot the 162 grain SST accurately, this bullet driven at 3070-3120fps makes an outstanding light to medium weight game bullet from point blank, out to 1000 yards although at the longer ranges, bone must be hit in order to ensure mechanical wounding and expansion. This bullet (annealed) is one of the better choices for long range work (beyond 600 yards) on large, tough bodied medium game. No other bullet can fully compare to the SST in this particular role which places huge and to a large extent, unrealistic demands on the bullet manufacturer.

The 162 grain Hornady A-Max is an excellent long range hunting bullet - although Hornady never designed the A-Max for hunting. Its only limitation is at close ranges where early bullet blow up can limit penetration on stout bodied medium game. On light bodied game (under 60kg/130lb) at impact velocities above 2900fps, entry wounds can be up to an inch in diameter, internal wounding is violent followed by an exit wound of a similar diameter to the entry wound.

On game weighing between 70 and 90kg at impact velocities above 2900fps, the A-Max tends to produce a normal caliber sized entry wound followed immediately by widely diffused wounding through vitals. The bullet then comes to rest in the offside muscle or bone. The A-Max often appears as though it has the potential to produce a complete failure (surface bullet blow up) but it never quite does. Kills are either fast or slightly delayed, game soon succumb to internal wounds. Personally, I cannot bring myself to trust a bullet that is incapable of penetrating through offside muscle and bone therefore I prefer to take neck shots on stout bodied game at close ranges when using the A-Max. For ordinary chest shooting at point blank ranges, the A-Max is best used on game weighing no more than 70kg (155lb).

At impact velocities of 2900 to 2700fps, the A-Max shows more uniform behavior across a wide range of game weights. Internal wounding is violent followed by exit wounds averaging 1” diameter on lighter bodied game. 80kg (180lb) is perhaps a realistic maximum body weight for the A-Max at these velocity parameters. Between 2600 and 2000fps, the A-Max comes into its own. Internal wounding is thorough, exit wounds can be very large due to the size of the remaining bullet fragments. From a velocity of 3100fps, the A-Max crosses the 2000fps mark at 775 yards. Beyond this range, the A-Max is somewhat reliant on bone to initiate expansion. The A-Max is able to produce wide wounding at 1600fps (1135 yards) when shots strike the lower scapular and leg bones of game.

At velocities of 2600 and below, the A-Max is again, best suited to game weighing up to 80kg (180lb) but can produce adequate results on game weighing up to 150kg (330lb). Hunters in the U.S have taken Elk sized game (320kg/700lb) with the A-Max however, the .30 caliber 178 and 208 grain A-Max are much more emphatic killers on big animals at long ranges.

Hornadys 175 grain Interlock bullets are extremely soft. Both, regardless of frontal area design, produce immediate and fast expansion at magnum velocities with a tendency to suffer excessive weight loss and limited penetration on lighter medium game. The 175 grain Interlock’s are best downloaded to 2600fps or less for woods hunting if deep penetration is to be expected. Neither is particularly well suited to hunting large bodied animals.

Nosler bullets include the 120 grain Ballistic Tip, the 140 grain Ballistic Tip, the 140 grain Partition, the 140 grain Accubond, the 150 grain Ballistic Tip, the 150 grain Partition, the 160 grain Accubond, the 160 grain Partition and 175 grain Partition. Nosler now also produce a solid copper 150 grain E-Tip, similar in design to Barnes, primarily intended for those who hunt in areas controlled by liberal local governments (not for actually hunting Liberals) where the use of lead based bullets has been banned.

The 140 grain BT is much like the Sierra GameKing when used at close ranges on light bodied game. Performance of this particular bullet is fair but certainly not spectacular. Of Nosler’s light 140 grain bullets, the 140 grain Nosler Accubond is the best performer, producing similar results to the InterBond but slightly more destructive at close ranges. The 150 grain Ballistic Tip is an excellent bullet when used on lighter medium game. Its BC is .493 and wounding is vivid out as far as 550 yards (2200fps). This bullet is similar in behavior to the 150 grain GameKing. The 150 grain Partition is a fast expanding, violent bullet however in comparison to its 160 grain counterpart, this projectile has a lower SD and BC.

The 160 grain Partition is simply outstanding at 7mm RM velocities. This is a fast expanding, violent wounding bullet. The 160 grain Partition is an excellent performer on light or lean bodied animals through to large bodied deer, reaching its limits but still entirely adequate for use on Elk sized game. It’s hard to believe how, decades after the introduction of the Partition, very few bullets manage to surpass its performance. So spectacular is its wounding on medium game, that occasionally, the target will split like an over ripe peach near entry and exit points - under the right conditions. The only major limiting feature of the Partition is its mild BC of .475. If this bullet had a BC of .6, no other bullet could compare. The Partition expands reliably down to velocities as low as 2000fps or 600 yards from a muzzle velocity of 3100fps.

The 160 grain Accubond is a reliable bullet. It’s BC of .531 is much higher than the traditional Partition. Unfortunately, wounding is not nearly as spectacular as the 160 grain Partition however the Accubond is a clean killing bullet. The Accubond does its best work at impact velocities above 2600fps (around 275 yards) but still produces relatively wide wounds at 2400fps, producing clean but slightly delayed killing. Nosler’s heavy 175 grain Partition is designed for Elk to Moose sized animals. Again, as is typical of the Partition, this bullet expands readily regardless of body weights encountered. The 175 grain Partition is adequately suited to large animals but cannot compare to a wider bore firing wider, heavier bullets. BC of this bullet is .519.

Swift produce the 140 grain A-Frame, the 150 grain Scirocco, the 160 grain A-Frame and 175 grain A-Frame bullets. The A-frames have fairly low BC’s, apart from the 175 grain A-Frame which has a BC of .493. Regardless of BC, these are very reliable medium to large medium game bullets. Performance of the A-Frame is very similar to Woodleigh Weldcore bullets. It must have taken a great deal of research to design both brands as neither aspect of performance (penetration versus wide wounding) is sacrificed. These bullets extract maximum terminal performance from the 7mm bore relative to its use on large heavy bodied game. To this end, the only way to increase wound channel diameters without sacrificing penetration, is to use a wider heavier bullet.

On game weighing up to 80kg (180lb), the 120 grain Barnes bullets perform much better than their heavier counterparts. The Tipped TSX has a fairly wide hollow point underneath the polymer tip which aids fast expansion and wound trauma. Having a BC of .373, the 120 grain TTSX driven at 3450fps gives fast killing at impact velocities above 2600fps (around 310 yards), producing clean but slightly delayed killing at 2400fps (around 400 yards). Beyond this range, the 120 grain TTSX loses velocity very quickly. The 140 grain TSX bullet is a tough customer. Like it’s 160 grain counterpart, this bullet will take a bull cattle beast broadside and exit. That said, wounds are narrow and this also is an unfortunate occurrence on light game. The 140 grain TSX is adequate for light to medium weight game, producing acceptable hydrostatic shock out to ranges of 250 to 275 yards (2600fps). Beyond this range, kills are as clean as can be obtained with a bow and broad head with the same delayed killing. Realistically, this projectile along with its 140 grain variations suit a niche, big tough medium game animals such as mature Boar, Sambar and Elk out to ranges of 300 yards. There is certainly no need for heavier Barnes bullet on these game weights.

The 160 through 175 grain Barnes bullets are best suited to large, heavy bodied game for which the 7mm bore itself is not that well suited. Sure, countless heavy game have been downed with cross body shots with the sevens but kills are never as emphatic or as clean as can be obtained with a medium or big bore. When utilizing the 160-175 grain Barnes bullets on heavy game, neck/spine shots and head shots produce the cleanest kills.

Woodleigh bullets of Australia produce 140,160 and 175 grain Weldcore bullets. BC of the 160 grain bullet is .486 and .530 for the 175 grain bullet. The long, high SD 160 and 175 grain Woodleigh bullets are tough, emphatic performers in the 7mm RM. The Weldcore bullets open up quickly on medium game (including lean animals) while penetration is very deep. Both the160 grain and 175 grain bullets are best used inside 300 yards to keep velocity high in order to maximize wounding. The Weldcore is adequate for use on light game, producing consistent but not widely diffused wounds, coming into its own on tough species of medium game.

Berger 7mm hunting bullets include the 140 grain VLD, the 168 grain VLD and the 180 grain VLD. Of these, the 168 and 180 grain VLD are very useful in the 7mm RM. The 168 grain VLD is similar in performance to the 162 grain A-Max. BC is a very high .643 and it is relatively easy to work up accurate, high velocity loads. As has been suggested throughout the 7mm texts, if the 168 grain VLD (or A-Max) is to be used on stout bodied game at very close ranges, rear lung, neck and head shots eliminate any possibility of shallow penetration that might otherwise occur with shoulder shots

When the 168 grain VLD is used on medium through to large bodied game at close range using the rear lung POI, the VLD performs in a reliable and spectacular manner. In this regard, the 168 grain VLD can tackle very large animals up to the size of Elk.

As the 168 grain VLD approaches 2600fps (330 yards), it comes into its own. Ordinary cross body shots produce exit wounds of up to 3” in diameter and killing is very fast. The 168 grain VLD continues to produce spectacular performance out at the 650 yard mark (2200fps) showing a gradual reduction in wounding, although still vivid, as the bullet approaches 2000fps (800 yards). Below 2000fps, the VLD needs to hit bone to promote wounding, remaining effective out at 975 yards (1800fps). Although some hunters have taken large game with the 168 grain VLD, this bullet is best suited to game weighing no more than 80kg (180lb).

Berger’s 180 grain VLD works extremely well in the 7mm Rem Mag. Muzzle velocities of 2900-2950fps are easily obtainable and the VLD is simple to work with. The reduction in muzzle velocity as opposed to the fast stepping 162 A-Max and 168 grain VLD can be used to great advantage in the 7mm Rem Mag, ensuring adequately deep penetration on large bodied game at close ranges, helped also by its excellent SD of .319.

The 180 grain VLD produces adequate cross body penetration on large bodied game up to 150kg (330lb) at point blank ranges and up to 320kg (700lb) as velocity falls below 2600fps (200 yards). Out at 1000 yards (1700fps), the 180 grain VLD does produce delayed kills. A hunting companion serving as a spotter is invaluable for this type of dedicated long range hunting.

Note: Update 1 Jan 2011. Berger have recently thickened the Jackets on the VLD line of projectiles due to concerns from hunters that the VLD was suffering mid air bullet blow up (perhaps due to aggressive twist rates in custom rifles?). The new 168 and 180 grain VLD projectiles are very stout and occasionally perform in a similar manner to the Sierra MatchKing, failing to produce broad, fast killing wounds. The 168 grain VLD is less effected by the thicker jacket, meeting enough resistance on medium game as to ensure fragmentation. Wounding at close ranges is excellent, kills are fast and clean and penetration is excellent. Killing is delayed at 1000 yards (below 1800fps).

The new 180 grain VLD can produce pin hole wounds on light bodied game at all ranges. This problem can be minimized by annealing the ogive. Place the VLD projectile in a pan of water with only the ogive exposed and heat the ogive with a blow/ Brule torch duplicating the traditional method for annealing brass. The annealing should be aggressive, as to cause a permanent color change. Accuracy is unaffected providing care is taken. When used un-annealed, the new style 180 grain VLD is more suited to heavy bodied medium game at extended ranges, filling its own niche.

Closing Comments

Personally, I believe that the 7mm Remington Magnum is one of the very best cartridges available for western hunters. The 7mm Rem Mag produces high power but at a recoil level that hunters can either tolerate or learn to tolerate. The 7mm Rem Mag is equally versatile in woods situations as it is at long range.

I often recommend the 7mm Rem Mag cartridge to clients and always state - “it’s a cartridge that never fails to please”. Nobody regrets buying a 7mm Remington Magnum, it can loaded fast, loaded for low recoil, loaded to produce minimum meat damage or loaded to produce maximum wounding for the fastest possible kills at extended ranges. The 7mm Rem Mag is not a good choice for less experienced shooters, best suited to intermediate experienced hunters. The 7mm Rem Mag is simple to work with and produces desirable results without the idiosyncrasies found in higher performance cartridge designs. The 7mm Rem Mag is essentially a headache free cartridge, a joy to shoot, a spectacular killer.

The 7mm Rem Mag is certainly not the most powerful 7mm. It also carries within its design, a degree of ignorance. The neck is short which can cause poor bullet to bore alignment when using hand loading dies of poor quality. The belt on the case head is absolutely pointless but it is there and there is nothing that can be done about it short of a complete re-design. Regardless of its theoretical flaws, this is an extremely efficient and effective medium game cartridge with little peer.

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ABOUT US

We are a small, family run business, based out of Taranaki, New Zealand, who specialize in cartridge research and testing, and rifle accurizing.